Ivereigh was educated at the Benedictine public school, Worth, and was at one point in his life a novice member of the Society of Jesus.

In 1989 he joined St Antony's College, Oxford, as a postgraduate student. In 1993 he completed a D.Phil. thesis for the University of Oxford titled Catholicism and Politics in Argentina: an Interpretation, with Special Reference to the Period 1930-1960 published as Catholicism and Politics in Argentina, 1810-1960 (New York: St Martin's Press; Basingstoke: Macmillan in association with St Antony's College, Oxford, 1995).

He has edited The Politics of Religion in an Age of Revival: Studies in Nineteenth-Century Europe and Latin America (London: Institute of Latin American Studies, 2000) and Unfinished Journey: the Church 40 Years after Vatican II: Essays for John Wilkins (New York; London: Continuum, 2003).

He has been Deputy Editor of The Tablet, editorial adviser to The Way, and associate editor of Godspy. He currently writes for America magazine's "In All Things" blog, while also contributing regularly to America magazine, Our Sunday Visitor, The Tablet, The Spectator, and others.

In October 2004, Ivereigh was appointed press secretary to the Archbishop of Westminster, working alongside his public affairs adviser, Sir Stephen Wall. After Sir Stephen's departure in May 2005, Ivereigh was appointed director for public affairs, a role which combined both positions. He has been credited with boosting the Archbishop's public image, which had been damaged by controversies over his dealings with paeophile priests. Ivereigh accompanied the Archbishop to Rome for the conclave that elected Pope Benedict XVI.

He was coordinator of The Da Vinci Code Response Group.

On 18 July 2006, Ivereigh resigned as the cardinal's director of public affairs following allegations by the Daily Mail. The allegations were the subject of legal proceedings initiated by Ivereigh in the High Court of Justice against Associated Newspapers Ltd. (ANL). A trial in February 2008 was inconclusive, but at the retrial in January 2009 [1] the jury unanimously found that Ivereigh had been libeled. He was awarded £30,000 in damages [2] and all costs [3], estimated at £3m. Ivereigh said his reputation had been "comprehensively vindicated".

Awarding costs against the Daily Mail, Justice Eady said that Ivereigh had achieved an “unqualified victory” against the newspaper’s “intransigence”, and had done so “in light of the sneering, belittling of his personality and his character made by the defendant”. Associated Newspapers, the judge said, "chose a strategy that in the end yielded nothing and are to be regarded as ‘in substance and in reality’ the losers."

Ivereigh is currently lead organiser of West London Citizens, part of the London Citizens alliance. In 2007, he founded the Strangers into Citizens campaign.

In August 2010 it was announced that Austen Ivereigh would head up a media group, known as Catholic Voices, which seeks to respond to opposition to the visit of the Pope to the UK in September 2010.